import sys
import pygame

def check_keydown_events(event,ship):
	"""响应按键"""
	if event.key == pygame.K_RIGHT:
		ship.moving_right = True
	elif event.key == pygame.K_LEFT:
		ship.moving_left = True
		
def check_keyup_events(event,ship):
	"""响应松开"""
	if event.key == pygame.K_RIGHT:
		ship.moving_right = False
	elif event.key == pygame.K_LEFT:
		ship.moving_left = False
 

def check_events(ship):
	"""响应按键和鼠标事件"""
	for event in pygame.event.get():
		if event.type == pygame.QUIT:
			sys.exit()
		elif event.type == pygame.KEYDOWN:
			check_keydown_events(event,ship)
		elif event.type == pygame.KEYUP:
			check_keyup_events(event,ship)

def update_screen(ai_settings, screen, ship):
	"""更新屏幕上的图像，并切换到新屏幕"""
	screen.fill(ai_settings.bg_color)
	ship.blitme()
	
	#让最近绘制的屏幕可见
	pygame.display.flip()
		
